Abstract: This study evaluates the chemopreventive effect of an aqueous extract of fresh leaves of Azadarichta indica against liver cancer. Twenty male rats (Spraque dawley), 150-250 g, were acclimatized for 1 week before use. The rats were divided randomly into 4 groups; cancer control group (C), cancer treated with 5% Azadarichta indica extract group (CAI), normal control group (N) and normal treated with 5% Azadarichta indica extract group (NAI) and each group contains 5 rats. Rats in group C and CAI were induced cancer by intraperitoneal injection of 200 mg kg-1 diethyl nitrosamine (DEN) as hepatocarcinogenesis initiator and then followed by 2-acetylaminofluorene as promoter of hepatocarcinogenesis (0.02% in food) for 2 weeks. The rats were then left for 2 weeks. The rats in group N and NAI were injected once intraperitoneally with corn oil and act as control. The plant was fed orally to CAI and NAI groups. Serum concentration of alpha-fetoprotein (AFP) as liver tumor marker was measured. Glutathione S-transferase (GST) and glutathione peroxidase (GPx) were measured in the serum and liver cytosol. The results of this study revealed that there is a significant difference (p≤0.05) between C and CAI groups in serum alpha-fetoprotein and, in serum and liver cytosol levels of glutathione S-transferase and glutathione peroxidase. While there was no significant difference (p≥0.05) between NAI and N group in GST and GPx level. As a conclusion from this study that the consumption of 5% of NEEM leaves aqueous extract resulted in complete inhibition of chemically induced hepatocarcinogenesis in Spraque dawley rats.